Expansion unit for mine ceiling support



Dec. 24, 1963 F. A. TEEPLE, JR

EXPANSION UNIT FOR MINE CEILING SUPPORT 2 Sheets-Sheet 1 Filed March 13, 1961 Qo INVENTOR.

FRANK A.TEEPLE,J!Z. BY

ATTO ZMEYS immuuilw Dec. 24, 1963 F. A. TEEPLE, JR 3,115,056

EXPANSION UNIT FOR MINE CEILING SUPPORT Filed March 13. 1961 2 Shee'ts-Sheet 2 United States Patent 3,115,056 EXPANSIQN UNIT FUR MINE CEILING SUPPGRT Frank A. 'Ieeple, Iha, Huntington, W. Va., assignor to H. K. Porter Company, Inc, Pittsburgh, Pin, a corporation of Pennsylvania Filed Mar. 13, 1961, Ser. No. 5,3ttl 15 Claims. (Cl. 35-24) The invention relates generally to the art of mining and primarily seeks to provide a novel expansion unit for anchoring the roof suspension bolts by which mine ceiling or root portions are supported.

Roof suspension bolts, or as popularly called, roof bolts, are now widely used. In the use of these bolts, holes are drilled vertically or sometimes at an angle, upwardly into the mine roof or ceiling, and supporting bolts directed through supporting plates or bars engaged with the roof or ceiling are inserted in the holes and anchored therein for securely supporting the engaged roof portions and portions adjacent thereto. The anchoring of the bolts is effected by employment of expansion units inserted in the roof bores and through which the bolts are threaded, means being included which are effective upon threading home of the bolts to expand the units and cause them to firmly grip the wall portions defining the bolt receiving bores. It is a purpose of the present invention to provide a novel form of expansion unit which can be easily and economically manufactured, and which is subject to being inserted into a receiving bore with great facility and capable of very securely anchoring a rod threaded therethrough.

An object of the invention is to provide an expander unit of the character stated including integrally connected and laterally spreadable sections or wings shaped to present a generally cylindrical exterior for engagement in a mine ceiling bore, an expander plug having an internally threaded bore therein and movable longitudinally between said wings, the wings and the plug having cooperating cam surfaces elfective when the plug is moved longitudinally to force the wings apart, and a bolt threadable through the plug bore for moving the plug longitudinally.

Another object of the invention is to provide an expander unit of the character stated wherein the spreadable wings are integrally connected through relatively narrow connecting members with a ring-like portion traversed by an abutment bar disposed to be en ageable by the upper end extremity of the bolt as it is threaded through the cooperating expander plug.

Another object of the invention is to provide an expander unit of the character stated wherein the integrally connected wings, the ring-like portion and the relatively narrow connecting members are shaped up from a simple fiat blank in which the side edges of each wing diverge toward end extremities remote from the ring-like portion, thereby to provide the cam edge surfaces for cooperation with camming surfaces on the cooperating plug when the blank has been finally shaped for such cooperation and is bent about the center traversed by the abutment bar of the ring in a manner for bringing the wings into opposed relation at opposite sides of the plug.

Another object of the invention is to provide an expander unit of the character stated wherein the cooperating wedge camming surfaces formed on the expander plug and on the wings which are integrally connected and bent into opposing relation so as to embrace the plug between them serve to retain the assembly of connected wing and plug secure against inadvertent falling out of the plug, said cooperating camming surfaces also being placed to take all wing spreading camming forces tangentially rather than radially, thereby assuring against Patented Dec. 24, 1963 2 deformation and compressive locking of the plug threads about the engaged bolt.

A further object of the invention is to provide an expander unit of the character stated in which the opposed and integrally connected wings are shaped to provide a generally cylindrical body embracing the plug as a selfretaining, two part assembly which cannot fall apart, said wings also including outwardly bulged portions intermediately of their free and connected end extremities and which provide initial contact areas for first contact with the mine ceiling bore during expansion of the unit therein.

A still further object of the invention is to provide an expander unit of the character stated wherein the cooperative wedge camming edge portions or surfaces on the expander plug and the opposed and integrally connected wings are opposed in a relation for interlocking, as by undercutting, thereby to assure proper camming pressure application during expanding of the unit, without danger of the wing edges being sprung outwardly beyond the camming surfaces on the expander plug.

With the above and other objects in View that will hereinafter appear, the invention will be more clearly understood by following the detailed description, the appended claims and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a top plan view of the expander unit.

FIGURE 2 is a side elevation of the two part assembly of FIGURE 1, one side wing being shown in the foreground.

FIGURE 3 is a longitudinal sectional view showing a mine ceiling bore and an expander unit placed in position for being anchored in the bore by turning of the anchor bolt, the view being taken in angular relation to the showing in FIGURE 2 to place one side wing at each side of the centrally shown expander plug.

FIGURE 4 is a detail plan View showing the blank from which the opposed and integrally connected wings and main body structure of the unit are shaped up.

FIGURE 5 is a top plan view of the expander plug, and FiGURE 6 is an inverted plan view thereof.

FIGURES 7 and 8 are side elevational views, the former looking at a side at which the wedge camming edges appear, and the latter at a side bearing 90 angular relation to the first mentioned side.

FIGURES 9 and 10 are horizontal sectional views taken respectively on the lines 99 and lid-10 on FIGURE 3.

In the example of embodiment of the invention herein disclosed, a section of a mine roof ceiling is shown at 5, the same being prepared with a drilled hole 6 in which to receive the expansion unit generally designated 7. The unit serves as an anchoring means for the bolt 8 with its head 9 bearing against the plate 10 which in turn supports the roof or ceiling as indicated at 11 in FIG- URE 3.

The improved expansion unit generally designated 7 includes the integral shell generally designated 12, and which is preferably formed from a flat metal blank, and the expander plug generally designated 13 and which, when the parts are completely shaped and properly assembled, is held within the shell against inadvertent fall out in a manner to be described hereinafter, and as shown in FIGURES 2 and 3.

The expansion unit shell generally designated 12 may be formed from the flat blank 14 as shown in FIGURE 4 and which includes a central ring-like portion 15 traversed centrally by an abutment bar 16, and two longitudinally aligned side wing portions 17 which are integrally connected with the ring-like portion by relatively narrow connecting members or straps 18. The side edges 19 of the Wing portions are designed as camming surfaces and diverge symmetrically with relation to the longitudinal center line of the blank and from the wing portion ends proximal to the ring-like portion 15 toward the wing portion ends remote from said ring-like portion. Toward the end extremities 2-0 of the wing portions remote from the ringlilte portion 15, the wing portion edges 1? are shaped to bear parallel relation as indicated at 21.

The expander plug generally designated 13 may be cast or forged to include a generally cylindrical body 22 having a threaded bore 23 formed axially therethrough and adapted to receive the anchoring bolt 3. At its upper extremity, the plug may be crowned from side to side as at 24, and recessed centrally about the threaded bore, as at 25, if desired. The plug 22 also includes two side leg dependencies 26, and these and the body 22 are shaped to provide wedge shape extensions 27 which are defined at their circumferentially or tangentially presented camming edges with undercut wedging surfaces 23. The dependencies or legs 26 also include radially outwardly presented shoulder portions 29 which merge with the cylindrical exterior of the plug body 22.

In conditioning the expansion unit for use the blank of FIGURE 4 is bent about its central ring-like portion 15 and the center abutment 16 thereof to the expander plug embracing or enclosing condition illustrated in FIG- URES 2 and 3, and at some time during this final conditioning of the shell, the fiat wing portions 17 are shaped into arcuate cross section so that the lateral edges can overlie the plug body 22 and oppose the outwardly presented shoulders 29 on the legs 27 and the undercut wedge camming edges 23 of said body and legs. Also, the wing portions 17 may be press shaped to provide cross grooving at 30 and resultant grip ribbing at 311. Also, in this shaping, there is provided a high point or area of initial ceiling bore contact during expansion of the unit, approximately at the location of the uppermost groove and the wall portions defining the same above and below, as indicated at 32 in FIGURE 3.

It will be apparent by reference to FIGURES 2 and 3 that when the integral shell 12 has been shaped about the expander plug in the manner illustrated, the plug is slidable longitudinally within the shell. By reason of the overlapping of the plug legs and body by the camming edge portions 19 of the shell, and the interfitting of the carnming edges 23 of the plug between said shell camming edges, provision is made for the desired loose assembly of the expander unit without any danger of inadvertent falling out of the expander plug from the enclosing shell.

In the use of the expander unit, the cooperating bolt 8 is threaded into the bore 23 in the expander unit plug after insertion through the receiving bore in the anchor plate 10, and the unit assembly is inserted in the mine ceiling bore 6 in the manner illustrated in FIGURE 3. Upon turning of the bolt and contact of its end with the abutment bar 15, the expander plug will be forced endwise between the shell wings by continued rotation of the bolt, and because of the cooperative engagement of the wedging or camming surfaces 2849, 28-19, as shown in FIGURES 3, 9 and 10, the wings will be spread apartlaterally about their narrow strap connections 18 and will be caused to firmly and securely anchor the expansion unit and the supported ceiling anchor plate 10 in the desired manner. It is to be understood that the grip ribbing 31 will indent itself in the ceiling bore 6, and during the expansion of the shell, the initial bore wall gripping contact will take place at the high point as previously described and indicated at 32 in FIGURE 3.

Many advantages flow from the particular structure and arrangement of parts disclosed herein.

The undecutting of the expander plug camming edges at 28 serves to provide for an interlocking of said edges and the cooperating camming edges on the shell in a manner for preventing outward deflection of the shell wing edges beyond the periphery of the engaged expander plug portions. Also, the specific arrangement of the camrning wedge projections on the expander plug and the placement thereof with relation to the cooperating edges on the shell wings serves to cause the expander plug to absorb the wing spreading force applied as the plug is moved along in the shell in a circumferential or tangential direction so as to avoid radial compressive straining of the plug and deformation of the plug and its threads such as mi ht cause a locking of the plug threads about the engaged bolt. This assures that there can be recovery of all bolts which it may be desired be removed from a mine ceiling after a room has been worked, and this is important from the standpoint of avoiding wastage of metal and unnecessary cost. The interlocking of the cumming wedge edge portions of plug and shell may be emphasized by shaping the shell edges to correspond generally to the undercutting of the plug wedges, if desired. Also, it will be apparent that the outwardly facing abutment shoulders 29 on the plug legs 26 will assure against radial inward deflection of the wing edges. See FIGURE 10.

It will be apparent by reference to FIGURE 2 of the drawings, that as the plug is forced downwardly between the shell wings incidental to the turning of the bolt 8, there can be an outward deflection of the lower extremities of the plug legs 25 so that engagement thereof in the bore 6 may contnibute toward the anchoring of the unit.

It will also be observed by reference to FIGURE 2 that the undercut camming surfaces 28 of the expander plug are angled downwardly and outwardly with relation to the plug axis, thereby to be effective in spreading the shell wing edges 19 outwardly or apart as well as the main central body portions of said wings, thus contributing toward improved clamping or anchoring efficiency in the mine ceiling bore.

It will be apparent by reference to FIGURES 2 and 3 of the drawings that the expansion nut is constantly guided within the enclosed shell and no misalignment between the nut and shell can take place. The shell is designed with a longitudinal curved surface on the inside as well as on the outside. With the formation of. the shell wings as shown and described, and the connection thereof integrally through the narrow straps 18 and ring-like portion 15, the spreading or clamping action of the Wings 17 is accomplished in lever action of the sec- 0nd class, said wings swinging outwardly about their intcgral connections at 18. Also, since the strap connectors 13 are narrow, they form least resistance points, and during the downward travel of the expander plug wedges 27--28 may be deformed outwardly into anchoring contact with the defining walls of the ceiling bore 6.

It is to be understood that the abutment bar 16 within the ring-like portion 15 is arranged so that the grain of the metal of which the shell is formed extends across said bar. With this arrangement a clean break away of the abutment bar will be made at its end connections with the ring-like member whenever there is a break away caused by engagement of the end extremity of the bolt 8 with said bar.

An outstanding feature of the disclosed expander unit is the inclusion therein of a low cost readily deformable shell and cooperating expander plug means for applying the shell to the surrounding or receiving bore 6 in a manner for causing the shell to conform accurately to said bore and apply uniform anchoring pressure within the bore.

Another outstanding feature is the self-locking action. As the unit is inserted in the bore, its high point bent portion at '32 engages in the bore, and while it is possible to freely move the unit into the bore, it is impossible to pull it out, because in trying to do so there is a wedging expansion downwardly of said high point contact and the lower extremities of the wings 17 are thus forced outwardly to accentuate said high point contacts to a degree preventing pull out.

The outward bending of the wings at 32 serves a purpose to present the edge portions .19 of the wings at a greater angle inward near the lower extremities thereof than at upper portions. This causes a first contacting of the wedge portions 13 of the plug at points below the high contact points '32 engaged in the bore 6 and assures the self-locking action referred to.

While example forms of the invention have been shown for purposes of illustration, it is to be clearly understood that various changes in the details of construction and arrangement of parts may be made without departing from the spirit and scope of the invention as defined in the appended claims.

-I claim:

1. An expansion unit of the character described including a body shell composed of laterally spreadab le opposed wings free of one another at lower end extremities and integrally connected at upper extremities by abutment and connecting strap means, said wings being shaped to provide a generally cylindrical exterior for engagement in a mine ceiling bore and present opposing edge portions providing wedge camming surfaces, an expander plug confined between said wings and slidable longitudinally there-between and having an internally threaded bolt receiving bore therethrough and a wedge shaped outward projection at each side and each extending for wing spreading caniming engagement and confinement against downward fall out between opposing wedge camming edges of the wings, and a bolt threadable through the plug bore for moving the plug downwardly in the shell and spreading the wings thereof outwardly, said abutment and connecting strap means includes a ring-like portion having an abutment bar transversin-g it centrally and in position for being engageable by the threaded end extremity of a bolt threaded through the plug, and a relatively narrow strap portion connecting the ring-like portion at each side to one of the wings at an upper end extremity remote from its free lower end extremity.

2. A unit as defined in claim 1 wherein the expander plug includes an upper generally cylindrical longitudinal body through which the threaded bore is formed, and depending spaced leg portions, each wedge shaped outward projection on the plug being formed in the generally cylindrical body and in one said leg portion.

3. A unit as defined in claim 1 wherein the body shell has a generally uniform wall thicknesses throughout its wings, the connecting strap portions, the ringlike portion and the abutment bar, and said wings having grip rib forming grooves pressed therein and being bowed outwardly intermediately of their upper and lower extremities to provide initial contact areas for first contact within a mine ceiling bore during expansion of the unit therein.

4. A unit as defined in claim 1 wherein the wedge camming edges on the wings and the wing spreading camming surfaces on the Wedge shaped outward projections on the expander plug are shaped to cooperatively interlock as the plug is moved along in the shell so as to prevent radial outward deflection of the wing edges beyond the outer surfaces of said wedge shaped outward projections.

5. A unit as defined in claim 1 wherein means are provided on the wedge camining edges of the wings and the wing spreading camming surfaces on the wedge shaped outward projections of the expander plug to absorb the wing spreading force applied as the plug is moved along in the shell in a circumferential or tangential direction so as to avoid radial compressive straining of the plug such as might bring about deformation of plug threads and compressive locking of the plug threads about the engaged bolt.

6. A unit as defined in claim 1 wherein means are provided on the wedge camming edges of the wings and the wing spreading camming surfaces of the wedge shaped outward projections on the expander plug to absorb the wing spreading force applied as the plug is moved along in the shell in a circumferential or tangential direction so as to avoid radial compressive straining of the plug such as might bring about deformation of plug threads and compressive locking of the plug threads about the engaged bolt, said last mentioned means on said wedge camming edges and the wing spreading camming surfaces of said wedge shaped outward projections also being shaped to cooperatively interlock as the plug is moved along in the shell so as to prevent radial outward deflection of the wing edges beyond the outer surfaces of said wedge shaped outward projections.

7. A unit as defined in claim 1 wherein the expander plug includes an upper generally cylindrical longitudinal body through which the threaded bore is formed, and depending spaced leg portions, each wedge shaped outward projection on the plug being formed in the generally cylindrical body and in one said leg portion, the wedge camming edges on the wings and the wing spreading camming surfaces on the wedge shaped outward projections on the expander plug having means for cooperative interlocking as the plug is moved along in the shell so as to prevent radial outward deflection of the wing edges beyond the outer surfaces of said wedge shaped outward projections.

8. A unit as defined in claim 1 wherein the expander plug includes an upper generally cylindrical longitudinal body through which the threaded bore is formed, and depending spaced leg portions each wedge shaped outward projection on the plug being formed in the generally cylindrical body and in one said leg portion, the wedge camming edges on the wings and the wing spreading carnming surfaces on the wedge shaped outward projections on the expander plug being provided with means shaped to cooperatively interlock as the plug is moved along in the shell so as to prevent radial outward deflection of the wing edges beyond the outer surfaces of said Wedge shaped outward projections, and wherein each depending leg portion on the plug includes outwardly facing abutment means engageable with wing edge portions to prevent inward deflection thereof during movement of the plug along in the shell.

9. A unit as defined in claim 1 wherein the expander plug includes an upper generally cylindrical longitudinal body through which the threaded bore is formed, and depending spaced leg portions, each wedge shaped outward projection on the plug being formed in the generally cylindrical body and in one said leg portion, the wedge camming edges on the wings and the wing spreading camming surfaces on the wedge shaped outward projections on the expander plug being provided with means shaped to cooperatively interlock as the plug is moved along in the shell so as to prevent radial outward deflection of the wing edges beyond the outer surfaces of said wedge shaped outward projections, and said last mentioned means also being cooperatively placed to absorb the wing spreading force applied as the plug is moved along in the shell in a circumferential or tangential direction so as to avoid radial compressive straining of the plug such as might bring about deformation of plug threads and compressive locking of the plug threads about the engaged bolt.

10. A unit as defined in claim 1 wherein the expander plug includes an upper generally cylindrical longitudinal body through which the threaded bore is formed, and depending spaced leg portions, each wedge shaped outward projection on the plug being formed in the generally cylindrical body and in one said leg portion, the wing spreading camming surfaces on the wedge shaped outward projections on the expander plug being undercut to cooperatively interlock with the wedge camming edges on the wings as the plug is moved along in the shell so as to prevent radial outward deflection of the wing edges beyond the outer surfaces of said outward projections, and said outward projection Wedge shaped surfaces and the wing edges being cooperatively placed to absorb the Wing spreading force applied as the plug is moved along in the shell in a circumferential or tangential direction so as to avoid radial compressive straining of the plug such as might bring about deformation of plug threads and compressive locking of the plug threads about the engaged bolt.

11. A unit as defined in claim 1 wherein the expander plug includes an upper generally cylindrical longitudinal body through which the threaded bore is formed, and depending spaced leg portions each wedge shaped outward projection on the plug being formed in the generally cylindrical body and in one said leg portion, the wedge camming edges on the wings and the wing spreading camrning surfaces on the wedge shaped outward projections on the expander plug being provided with means shaped to cooperatively interlock as the plug is moved along in the shell so as to prevent radial outward deflection of the wing edges beyond the outer surfaces of said wedge shaped outward projections, and wherein each depending leg portion on the plug includes outwardly facing abutment means engageable with wing edge portions to prevent inward deflection thereof during movement of the plug along in the shell, and said wedge shaped outward projections also being angled downwardly and outwardly with relation to the axis of the plug so as to be effective to spread the edges of each shell wing apart as well as the main central body portions of the opposed wings.

12. A unit as defined in claim 1 wherein said abutment bar is arranged so that the grain of the metal of which the shell is formed extends thereacross so as to cause a clean break away of the abutment bar at its end connections with the ring-like member whenever there is a break away caused by bolt end contact.

13. A unit as defined in claim 1 wherein the shell wings are bent outwardly intermediately of the upper and lower extremities thereof to provide high point contact areas for self retaining engagement in a receiving bore, and there being inwardly facing first contact portions on the wing edge portions downwardly of said high point areas and placed for initial contact by the wedge shaped projections of the plug when it is engaged downwardly against said first contact portions.

14. A unit as defined in claim 1 wherein the shell wings are bent outwardly intermediately of the upper and lower extremities thereof to provide high point contact areas for self retaining engagement in a receiving bore, and there being complementary provision for high point initial contact of the wedge projection means and the wing edges downwardly of said high point areas to provide for initial outward pressure against the wings at their lower end extremities as the plug is forced along between the wings by a pull on the bolt tending to remove the unit from the bore prior to proper expansion of the unit in the bore.

15. An expansion unit of the character described including a body shell composed of laterally spreadable opposed wings free of one another at lower end extremities and integrally connected at upper extremities by abutment and connecting strap means, said wings being shaped to provide a generally cylindrical exterior for engagement in a mine ceiling bore and presenting opposing edge portions providing longitudinally extending wedge camming surfaces, an expander plug confined between said wings and slidable longitudinally therebetween and having an internally threaded bolt-receiving longitudinal bore therethrough, a wedge shaped outward projection extending longitudinally at opposite sides of said plug, each projection terminating at opposite longitudinal edges in radially undercut wing spreading camming surfaces in confining interlocking engagement with the wedge camming surfaces of said wings to prevent radial outward deflection of the wing edge portions beyond the outer surfaces of said outward projections as the plug is moved along in the shell, a bolt threadable through the plug bore for engagement with said abutment and connecting strap means for moving the plug in the shell and spreading the wings thereof outwardly, said expander plug including an upper generally cylindrical longitudinal body through which the threaded bore is formed and depending spaced leg portions, and each wedge shaped outward projection on the plug being formed in the generally cylindrical body and in one said leg portion.

References Cited in the file of this patent UNITED STATES PATENTS 436,307 Diss Sept. 9, 1890 1,345,908 Barnard July 6, 1920 1,567,687 Tomkinson Dec. 29, 1925 1,567,713 Corser et a1 Dec. 29, 1925 1,639,223 Fisher Aug. 16, 1927 2,393,606 Brush Jan. 29, 1946 2,753,750 Dempsey July 10, 1956 2,832,253 Allimann 1. Apr. 29, 1958 2,952,129 Dempsey Sept. 13, 1960 3,000,254 Hottenstein Sept. 19, 1961 

1. AN EXPANSION UNIT OF THE CHARACTER DESCRIBED INCLUDING A BODY SHELL COMPOSED OF LATERALLY SPREADABLE OPPOSED WINGS FREE OF ONE ANOTHER AT LOWER END EXTREMITIES AND INTEGRALLY CONNECTED AT UPPER EXTREMITIES BY ABUTMENT AND CONNECTING STRAP MEANS, SAID WINGS BEING SHAPED TO PROVIDE A GENERALLY CYLINDRICAL EXTERIOR FOR ENGAGEMENT IN A MINE CEILING BORE AND PRESENT OPPOSING EDGE PORTIONS PROVIDING WEDGE CAMMING SURFACES, AN EXPANDER PLUG CONFINED BETWEEN SAID WINGS AND SLIDABLE LONGITUDINALLY THEREBETWEEN AND HAVING AN INTERNALLY THREADED BOLT RECEIVING BORE THERETHROUGH AND A WEDGE SHAPED OUTWARD PROJECTION AT EACH SIDE AND EACH EXTENDING FOR WING SPREADING CAMMING ENGAGEMENT AND CONFINEMENT AGAINST DOWNWARD FALL OUT BETWEEN OPPOSING WEDGE CAMMING EDGES OF THE WINGS, AND A BOLT THREADABLE THROUGH THE PLUG BORE FOR MOVING THE PLUG DOWNWARDLY IN THE SHELL AND SPREADING THE WINGS THEREOF OUTWARDLY, SAID ABUTMENT AND CONNECTING STRAP MEANS INCLUDES A RING-LIKE PORTION HAV- 